Novel drug treatments for pain in advanced cancer and serious illness: a focus on neuropathic pain and chemotherapy-induced peripheral neuropathy.

Drugs that are commercially available but have novel mechanisms of action should be explored as analgesics. This review will discuss haloperidol, miragabalin, palmitoylethanolamide (PEA), and clonidine as adjuvant analgesics or analgesics. Haloperidol is a sigma-1 receptor antagonist. Under stress and neuropathic injury, sigma-1 receptors act as a chaperone protein, which downmodulates opioid receptor activities and opens several ion channels. Clinically, there is only low-grade evidence that haloperidol improves pain when combined with morphine, methadone, or tramadol in patients who have cancer, pain from fibrosis, radiation necrosis, or neuropathic pain. Miragabalin is a gabapentinoid approved for the treatment of neuropathic pain in Japan since 2019. In randomized trials, patients with diabetic neuropathy have responded to miragabalin. Its long binding half-life on the calcium channel subunit may provide an advantage over other gabapentinoids. PEA belongs to a group of endogenous bioactive lipids called ALIAmides (autocoid local injury antagonist amides), which have a sense role in modulating numerous biological processes in particular non-neuronal neuroinflammatory responses to neuropathic injury and systemic inflammation. Multiple randomized trials and meta-analyses have demonstrated PEA's effectiveness in reducing pain severity arising from diverse pain phenotypes. Clonidine is an alpha2 adrenoceptor agonist and an imidazoline2 receptor agonist, which is U.S. Federal Drug Administration approved for attention deficit hyperactivity disorder in children, Tourette's syndrome, adjunctive therapy for cancer-related pain, and hypertension. Clonidine activation at alpha2 adrenoceptors causes downstream activation of inhibitory G-proteins (Gi/Go), which inhibits cyclic Adenosine monophosphate (AMP) production and hyperpolarizes neuron membranes, thus reducing allodynia. Intravenous clonidine has been used in terminally ill patients with poorly controlled symptoms, in particular pain and agitation.

Comparison of the Efficacies of Dexmedetomidine and Clonidine in Preventing Postoperative Nausea and Vomiting in Paediatric Patients Undergoing Abdominal Surgeries.

Background Postoperative nausea and vomiting (PONV) is a common complication in paediatric patients undergoing abdominal surgeries. Dexmedetomidine and clonidine, both α2-adrenergic agonists, have been proposed as potential treatments for PONV due to their antiemetic properties. This study aimed to compare the efficacies of dexmedetomidine and clonidine in the prevention of PONV in paediatric patients following abdominal surgeries Methods Eighty patients, aged five to 12 years undergoing abdominal surgeries under general anaesthesia were enrolled in this study. Patients were randomly assigned to receive either a single intravenous dose of 0.5 µg/kg of dexmedetomidine (Group D; n=40) or 1 µg/kg of clonidine (Group C; n = 40) 10 minutes before extubation. PONV was recorded for the next 24 hours. Results The baseline characteristics of patients were comparable. A higher proportion of patients in the clonidine group developed PONV as compared to the dexmedetomidine group (27.5% vs 20.0%, p=0.189). The visual analogue scale (VAS) score of group C was higher than that of group D (1.38±1.55 vs 1.00±1.26) but was not statistically significant. The Paediatric Anaesthesia Emergence Delirium (PAED) scale score or emergence agitation (EA) score was higher in group C during recovery time. The mean arterial pressures and the heart rates were comparable in both groups. No significant side effects were reported. Conclusion Our study concludes that dexmedetomidine and clonidine effectively control PONV in paediatric abdominal surgery, with no significant difference in incidence or severity. Dexmedetomidine significantly reduced PAED scale scores during recovery, indicating better control of EA. The two treatments showed comparable mean arterial pressures and heart rates without significant side effects.

Identification of Catecholamine and Drug Target α2A-Adrenoceptor in Human Testis and Human Testicular Peritubular Cells.

Background: Clonidine has been used in clinical medicine, e.g., to treat high blood pressure and other conditions. Animal studies have linked its use to impairments of male reproductive functions, and although only a few reports exist for the human species, such actions may exist in man as well. The underlying reasons and, specifically, possible actions of clonidine at the level of the testis are not known. Introduction: Clonidine is an agonist at the α2A-adrenoceptor (ADRA2A), which, as data bank mining indicated, is expressed by several cells of the human testis. The human testis and most of its cells are, however, not readily accessible to experimental testing. Cells from the peritubular wall compartment (human testicular peritubular cells; HTPCs) are the exception. Methods and Results: As shown by immunohistochemical/immunocytochemical and PCR techniques these cells express ADRA2A and retain expression upon isolation and culture. When tested over a concentration range (1-1000 µM) and 24 h, clonidine did not visibly affect HTPC morphology but significantly stimulated IL6 mRNA levels in a concentration-dependent manner. ELISA measurements of cell culture supernatants confirmed a stimulatory action of clonidine (10 µM) on secreted IL6. When examined in collagen gel contraction assays of HTPCs, clonidine (10 µM) exerted a slight relaxing action, while a proteomic study revealed that clonidine (10 µM) did not significantly change cellular protein abundance of HTPCs after 24 h (data available via ProteomeXchange with identifier PXD052220). Conclusion: Thus, ADRA2A-bearing cells in the human testis are targets for catecholamines and drugs such as clonidine. The results of this HTPCs-focused study only show the tip of the iceberg. It is likely that catecholamines/catecholaminergic drugs have the potential to interfere with human testicular functions.

A historical perspective on clonidine as an alpha-2A receptor agonist in the treatment of addictive behaviors: Focus on opioid dependence.

Clonidine operates through agonism at the alpha-2A receptor, a specific subtype of the alpha-2-adrenergic receptor located predominantly in the prefrontal cortex. By inhibiting the release of norepinephrine, which is responsible for withdrawal symptoms, clonidine effectively addresses withdrawal-related conditions such as anxiety, hypertension, and tachycardia. The groundbreaking work by Gold et al. demonstrated clonidine's ability to counteract the effects of locus coeruleus stimulation, reshaping the understanding of opioid withdrawal within the field. In the 1980s, the efficacy of clonidine in facilitating the transition to long-acting injectable naltrexone was confirmed for individuals motivated to overcome opioid use disorders (OUDs), including physicians and executives. Despite challenges with compliance, naltrexone offers sustained blockade of opioid receptors, reducing the risk of overdose, intoxication, and relapse in motivated patients in recovery. The development of clonidine and naltrexone as treatment modalities for OUDs, and potentially other addictions, including behavioral ones, underscores the potential for translating neurobiological advancements from preclinical models (bench) to clinical practice (bedside), ushering in innovative approaches to addiction treatment.

Targeting α1- and α2-adrenergic receptors as a countermeasure for fentanyl-induced locomotor and ventilatory depression.

This study assessed the ability of α1 and α2-adrenergic drugs to decrease fentanyl-induced locomotor and ventilatory depression. Rats were given saline or fentanyl, followed by: (1) naltrexone, (2) naloxone, (3) nalmefene, (4) α1 agonist phenylephrine, (5) α1 antagonist prazosin, (6) α1D antagonist BMY-7378, (7) α2 agonist clonidine, (8) α2 antagonist yohimbine or (9) vehicle. All µ-opioid antagonists dose-dependently reversed fentanyl-induced locomotor and ventilatory depression. While the α1 drugs did not alter the effects of fentanyl, clonidine dose-dependently decreased locomotion and respiration with and without fentanyl. Conversely, yohimbine given at a low dose (0.3-1 mg/kg) stimulated ventilation when given alone and higher doses (>1 mg/kg) partially reversed (∼50 %) fentanyl-induced ventilatory depression, but not locomotor depression. High doses of yohimbine in combination with a suboptimal dose of naltrexone reversed fentanyl-induced ventilatory depression, suggestive of additivity. Yohimbine may serve as an effective adjunctive countermeasure agent combined with naltrexone to rescue fentanyl-induced ventilatory depression.

Identification of a Conversion Factor for Dexmedetomidine to Clonidine Transitions.

OBJECTIVE: To determine a conversion factor for use when switching from dexmedetomidine infusion to enteral clonidine in critically ill neonates. METHODS: This was an observational, retrospective review of conversions from dexmedetomidine to -clonidine, performed in a neonatal intensive care unit (NICU) between January 2020 and December 2021. Both initial conversion factors and those resulting after a 48-hour titration period were examined. Sedation and withdrawal scores were measured, and doses were titrated based on a standardized practice within the unit. RESULTS: A total of 43 dexmedetomidine to clonidine conversions were included. The median (IQR) dexmedetomidine dose prior to conversion was 17.4 (11.3-24.0) mcg/kg/day (0.7 mcg/kg/hr) and the median (IQR) enteral clonidine dose post titration was 7.8 (4.7-9.3) mcg/kg/day (2 mcg/kg every 6 hours). This equated to a post-titration conversion factor of approximately 0.42. All neonates had also received opioid infusions while on dexmedetomidine and 60% were on concurrent opioids at the time of the clonidine conversion. CONCLUSIONS: Neonatal clinicians may find the conversion factor identified in this study a useful starting point when converting from dexmedetomidine infusion to enteral clonidine in practice and should be -reminded of the most important steps in conversions (monitoring and follow-up) owing to the variability in this patient group. More studies are needed to elucidate the impact of patient-specific factors on this -conversion process.

A Comparative Study Between Intravenous Esmolol and Oral Clonidine in Attenuating Hyperdynamic Cardiovascular Response to Laryngoscopy and Endotracheal Intubation.

Background In today's era of anesthesia, balanced anesthesia is the main basis of patient care and pain management. Of all the medications given during general anesthesia, premedication, induction agents, and muscle relaxants play a major role in keeping the hemodynamics properly under control. When laryngoscopy is performed to intubate, a pain stimulus will be generated, leading to a rise in blood pressure and heart rate. This stimulus can be avoided without any complications if appropriate premedication is given to the patient at the appropriate dosage. In this research, we compare the influence of injection esmolol and oral clonidine during the time of induction as premedications to suppress the hemodynamic response. Material and methods In a prospective randomized controlled trial, 90 patients were divided into three groups: Group E (esmolol) received 2 mg/kg IV esmolol diluted in 0.9% NS two minutes pre-anesthesia; Group C (clonidine) received oral clonidine 4 mcg/kg 90 minutes pre-anesthesia; and Group P (placebo) received IV normal saline and oral water. Blood pressure, heart rate, and mean arterial pressure were measured at baseline and seven subsequent time points. Results The study compared systolic blood pressure (SBP), mean arterial pressure (MAP), and diastolic blood pressure (DBP) changes over seven minutes in three groups, clonidine (Group C), placebo (Group P), and esmolol (Group E). At one minute, Group E showed a consistent MAP decrease from 95.21 mmHg to 85.92 mmHg, while Group C and Group P exhibited fluctuating trends. DBP decreased across all groups, with Group P ending highest (77.7 mmHg) and Group C lowest (66.8 mmHg). Group E's SBP decreased steadily from 126.2 mmHg to 118.0 mmHg, Group C decreased from 128 mmHg to 116.1 mmHg, and Group P showed more erratic fluctuations in SBP, DBP, and MAP. Conclusion These findings suggest that intravenous esmolol shows a good hemodynamic response having superior control over heart rate and getting the pressure under control quickly without major drop compared with the clonidine and placebo groups.

Comparative Study of the Effects of Clonidine and Tranexamic Acid on Intraoperative Bleeding in Rhinoplasty: A Clinical Trial.

Introduction: The present study was conducted to compare the effects of clonidine and tranexamic acid on the volume of bleeding and quality of the surgical field in terms of bleeding in candidates who underwent rhinoplasty. Methods: In this two-sided clinical trial, candidates eligible for rhinoplasty were randomly assigned to two treatment groups: tranexamic acid and clonidine. The first group received tranexamic acid at a dose of 700 µg/kg of body weight 2 hours before the surgical procedure, whereas the second group received clonidine orally at a dose of 2 mg/kg of body weight, 90 minutes before surgery. Subsequently, the volume of bleeding was calculated based on the amount of blood collected via suction and in blood-soaked gauze, which was previously weighed. Results: Among the 92 patients who underwent rhinoplasty, 82% were women. The mean age and standard deviation (SD) of individuals who underwent rhinoplasty were 29.22 ± 8.50 years. There were no significant differences between the two treatment groups in terms of age, gender, and body mass index. The volume of blood collected via suction during rhinoplasty, categorized into surgery duration <63 minutes and ≤63 minutes, showed a significant difference between the 2 treatment groups. Conclusion: The use of tranexamic acid, compared with clonidine, resulted in lesser intraoperative bleeding and better surgical field quality. Considering the superior effectiveness of tranexamic acid in reducing intraoperative bleeding, it is recommended to use tranexamic acid instead of clonidine in rhinoplasty.

Topical Clonidine Accelerates Cutaneous Wound Healing in Diabetic Rats by Regulating the Expression of Related Cytokine Signaling.

Based on the analgesic and anti-inflammatory effects of clonidine in previous studies, we hypothesized that clonidine could accelerate wound healing in rats by regulating the expression of related cytokines. In this study, the wound healing effect of clonidine was evaluated using an excision wound model in diabetic rats and a HaCaT cell model. The wounds were treated daily with topical clonidine. The results analyzed by ImageJ2 software show that the wounds of the rats that were treated with 15 ng/mL clonidine recovered faster, and the wound size was also significantly reduced compared to the control group. Western blot assays determined that clonidine induced an increase in the expression of vascular growth factors, namely, Ang-1, Ang-2, and VEGF. Moreover, clonidine demonstrated a rescuing effect on JAK2 within the JAK/STAT pathway by inhibiting SOCS3 expression, leading to decreased SOCS3 levels and increased expression of JAK2 and phospho-STAT3. Histopathological analysis revealed that clonidine promoted complete epithelial repair and minimized inflammation in skin tissue. Additionally, clonidine stimulated HaCaT cell proliferation in vitro and enhanced cellular energy levels in the presence of AGEs. In conclusion, clonidine promoted vascular growth and wound healing by stimulating the expression of cytokines that are beneficial for wound healing.

The alpha2-adrenergic receptor agonist clonidine protects against cerebral ischemia/reperfusion induced neuronal apoptosis in rats.

Apoptosis is the crucial pathological mechanism following cerebral ischemic injury. Our previous studies demonstrated that clonidine, one agonist of alpha2-adrenergic receptor (α2-AR), could attenuate cerebral ischemic injury in a rat model of middle cerebral artery occlusion/reperfusion (MCAO/R). However, it's unclear whether clonidine exerts neuroprotective effects by regulating neuronal apoptosis. In this study, we elucidated whether clonidine can exert anti-apoptotic effects in cerebral ischemic injury, and further explored the possible mechanisms. Neurological deficit score was measured to evaluate the neurological function. TTC staining was used for the measurement of brain infarct size. Hematoxylin-Eosin (HE) staining was applied to examine the cell morphology. TUNEL and DAPI fluorescent staining methods were used to analyze the cell apoptosis in brain tissue. Fluorescence quantitative real-time PCR was performed to assess the gene expression of Caspase-3 and P53. Western blotting assay was applied to detect the protein expression of Caspase-3 and P53. The results showed that clonidine improved neurological function, reduced brain infarct size, alleviated neuronal damage, and reduced the ratio of cell apoptosis in the brain with MCAO/R injury. moreover, clonidine down-regulated the gene and protein expression of Caspase-3 and P53 which were over-expressed after MCAO/R injury. Whereas, yohimbine (one selective α2-AR antagonist) mitigated the anti-apoptosis effects of clonidine, accompanied by reversed gene and protein expression changes. The results indicated that clonidine attenuated cerebral MCAO/R injury via suppressing neuronal apoptosis, which may be mediated, at least in part, by activating α2-AR.

Alpha2 Agonist Use in Critically Ill Adults: A Focus on Sedation and Withdrawal Prevention.

The management of sedation in critically ill adults poses a unique challenge to clinicians. Dexmedetomidine, an α2 agonist, has a unique mechanism and favorable pharmacokinetics, making it an attractive intravenous option for sedation and delirium in the intensive care unit. However, patients may be at risk for withdrawal with prolonged use, adding to the complexity of sedation and agitation management in this patient population. Enteral α2 agents have the benefit of cost savings and ease of administration, thus playing a role in the ability to decrease intravenous sedative use and prevent dexmedetomidine withdrawal. Clonidine and guanfacine are the two most common enteral α2 agents utilized for this purpose, however, there is a paucity of evidence regarding the comparative benefit between the two agents. The decision to use one vs the other agent should be determined based on their differing pharmacology, pharmacokinetics, and side effect profile. The most effective dosing strategy for these agents is also unknown. Ultimately, more robust literature is required to determine enteral α2 agonists place in therapy. This narrative review evaluates the currently available literature on the use of α2 agonists in critically ill adults with an emphasis on sedation, delirium, and withdrawal.

Comparison of alpha-2 agonist versus alpha-1 antagonist for post-traumatic stress disorder-associated nightmares in pediatric patients.

Introduction: Posttraumatic stress disorder (PTSD) in children and adolescents has a high prevalence of accompanying sleep disturbances. Currently, pediatric treatment of PTSD-related nightmares is extrapolated from adult studies. This study aims to determine the effectiveness and safety of clonidine and guanfacine compared with prazosin for the treatment of PTSD-related nightmares. Methods: This was a retrospective, single-center, medical record review of patients 5 to 17 years old admitted to an inpatient psychiatric unit from January 2015 to September 2021. Patients with a new initiation of an alpha-2 agonist (clonidine or guanfacine) or an alpha-1 antagonist (prazosin) with a diagnosis of PTSD, other trauma- or stressor-related disorder or unspecified anxiety disorder were included. The primary endpoint was the percentage of patients with a decrease in the frequency of nightmares. Results: A total of 59 patients were included in the study: 37 in the alpha-2 agonist group and 22 in the alpha-1 antagonist group. There was no statistically significant difference in reduction of nightmares with both groups having a high percentage of patients showing response (alpha-2 agonist: 91.9%, alpha-1 antagonist: 86.4%). Time to decrease in nightmares was comparable between groups with a relatively quick onset. Within the alpha-2 agonist group, clonidine (1.59 ± 1.06 days) compared with guanfacine (3.18 ± 1.74 days) had a statistically significant faster time to reduction in nightmares (p = .005). Discussion: Both pharmacologic classes of medications were effective treatment options for pediatric PTSD-associated nightmares with a low incidence of adverse effects. There was a quick time to onset seen with all agents.

Clonidine for post-traumatic stress disorder: a systematic review of the current evidence.

Background: Clonidine is a centrally acting anti-adrenergic agent that may have applications in post-traumatic stress disorder (PTSD), particularly for sleep.Objective: In this systematic review, we aimed to summarize the effect of clonidine on sleep quality and duration, nightmares, and PTSD symptom severity in adults with PTSD.Method: PubMed (Medline), Embase, PsycINFO, CINAHL, and clinicaltrials.gov were searched up to April 2023. Studies on clonidine use in adult PTSD patients reporting data on the effect on sleep, nightmares, and PTSD symptoms were included. A narrative summary and a meta-analysis of the study findings are presented.Results: Ten reports, accounting for N = 569 patients with PTSD (145 on clonidine and 436 controls), were included in the final selection. There were four case reports, four observational studies, one non-blind clinical trial, and one crossover randomized controlled trial (RCT). Median clonidine dose was 0.15 mg/day (range: 0.1-0.5 mg/day). Median follow-up time was 31 days (range: 3 days to 19 months). The quality of the evidence was rated from very low to low. There was marked between-study heterogeneity and low power in the individual studies, but many reported improved sleep quality, nightmare reduction, and improvement of PTSD symptoms for patients treated with clonidine. Meta-analysis was only possible for two studies reporting the effect of clonidine on nightmares, and showed no difference from the comparator (i.e. prazosin or terazosin) (odds ratio: 1.16; 95% confidence interval: 0.66 to 2.05), potentially pointing towards non-inferiority between these medications.Conclusions: Future research, such as well-powered RCTs, is needed to identify the efficacy in the lower dose range and the most suitable treatment group, and to obtain good evidence on the effects of clonidine in the treatment of sleep disorders related to PTSD.

Post-traumatic stress disorder (PTSD) is associated with hyperarousal and sleep disorders, reflecting adrenergic nervous system involvement.The use of anti-adrenergic drugs to target the sympathetic activation in PTSD is rational. However, previous reports on prazosin, a peripherally acting agent, yielded weak evidence.Clonidine, a central adrenergic antagonist, shows promise in improving sleep, nightmares, and PTSD symptoms, but further research is needed because the quality of the current evidence is low.

Recent advances in pharmacological management of attention-deficit/hyperactivity disorder: moving beyond stimulants.

INTRODUCTION: Attention-deficit/hyperactivity disorder (ADHD) is a common neurobehavioral disorder characterized by impairing inattention and/or hyperactivity and impulsivity in children and adults. Although medications have been available to treat ADHD symptoms for decades, many are stimulant formulations. Stimulants, such as amphetamine and methylphenidate, are available in more than two dozen formulations, but all have similar adverse effects and carry a risk of misuse and dependence. AREAS COVERED: In the United States (US), several nonstimulants are available to treat ADHD. Two, including atomoxetine and viloxazine extended-release (ER), are approved by the Food and Drug Administration for the treatment of ADHD in children and adults. Two others, clonidine ER and guanfacine ER, are only approved for children and adolescents in the US. Several other compounds are under investigation. Drugs in Phase 3 trials include centanafadine, solriamfetol, and L-threonic acid magnesium salt. Efficacy and safety data for nonstimulants is presented. EXPERT OPINION: Although many effective formulations for the treatment of ADHD are available, more than 33% of children and 50% of adults discontinue treatment during the first year. The lack of individual drug response and tolerability are reasons many stop treatment. The development of new nonstimulants may offer hope for patients who need medication alternatives.

A Comparative Study of the Antiemetic Effects of α2-Adrenergic Receptor Agonists Clonidine and Dexmedetomidine against Diverse Emetogens in the Least Shrew (Cryptotis parva) Model of Emesis.

In contrast to cats and dogs, here we report that the α2-adrenergic receptor antagonist yohimbine is emetic and corresponding agonists clonidine and dexmedetomidine behave as antiemetics in the least shrew model of vomiting. Yohimbine (0, 0.5, 0.75, 1, 1.5, 2, and 3 mg/kg, i.p.) caused vomiting in shrews in a bell-shaped and dose-dependent manner, with a maximum frequency (0.85 ± 0.22) at 1 mg/kg, which was accompanied by a key central contribution as indicated by increased expression of c-fos, serotonin and substance P release in the shrew brainstem emetic nuclei. Our comparative study in shrews demonstrates that clonidine (0, 0.1, 1, 5, and 10 mg/kg, i.p.) and dexmedetomidine (0, 0.01, 0.05, and 0.1 mg/kg, i.p.) not only suppress yohimbine (1 mg/kg, i.p.)-evoked vomiting in a dose-dependent manner, but also display broad-spectrum antiemetic effects against diverse well-known emetogens, including 2-Methyl-5-HT, GR73632, McN-A-343, quinpirole, FPL64176, SR141716A, thapsigargin, rolipram, and ZD7288. The antiemetic inhibitory ID50 values of dexmedetomidine against the evoked emetogens are much lower than those of clonidine. At its antiemetic doses, clonidine decreased shrews' locomotor activity parameters (distance moved and rearing), whereas dexmedetomidine did not do so. The results suggest that dexmedetomidine represents a better candidate for antiemetic potential with advantages over clonidine.

Clonidine Patch for Tourette Syndrome With Attention-Deficit/Hyperactivity Disorder.

OBJECTIVE: To explore the efficacy and safety of clonidine adhesive patch in Tourette syndrome (TS) patients with comorbid attentiondeficit/hyperactivity disorder (ADHD). METHODS: This study was conducted on a sample of children and adolescents with TS who had comorbid ADHD between May 2012 and March 2015. The patients were diagnosed according to Diagnostic and Statistical Manual of Mental Disorders Fourth Edition, and were randomly assigned to four different dose groups: 1.0 mg/week, 1.5 mg/week, 2.0 mg/week and placebo group, and the symptom was evaluated by Swanson, Nolan, and Pelham Rating Scale, Version IV (SNAP-IV) and Yale Global Tic Severity Scale scales every 2 weeks. The primary outcome was tic disorders (TD) effective rate at week 8. RESULTS: One hundred and twenty-seven TS patients with comorbid ADHD in 2.0 mg/week (n=35), 1.5 mg/week (n=27), 1.0 mg/week (n=36) and placebo groups (n=29) were included in this subgroup analysis. The TD effective rate of the 2.0 mg, 1.5 mg, and 1.0 mg groups at week 8 were significantly better than that in placebo group (85.7%, 81.5%, and 86.1% vs. 20.7%, all p<0.0001). All groups demonstrated significant improvements in SNAP-IV total scale scores compared to baseline (p=0.0004), with treatment groups showing only a trend for better performance compared to placebo group at week 8, without statistical differences (22.1±15.41, 21.3±11.96, and 21.2±12.48 vs. 26.0±13.37, p=0.3385). A total of 9 adverse reactions occurred, all recovered spontaneously without additional medication. CONCLUSION: Clonidine adhesive patch could safely and effectively reduce the tic symptoms of TS patients with comorbid ADHD, and might be potentially helpful in the ADHD symptoms control.

Not first-line antihypertensive agents, but still effective-The efficacy and safety of imidazoline receptor agonists: A network meta-analysis.

Cardiovascular disorders are the leading cause of death in the world. Many organ diseases (kidney, heart, and brain) are substantially more prone to develop in people with hypertension. In the treatment of hypertension, first-line medications are recommended, while imidazoline receptor agonists are not first-line antihypertensives. Our goal was to conduct a network meta-analysis to assess the efficacy and safety of imidazoline receptor agonists. The meta-analysis was performed following the PRISMA guidelines using the PICOS format, considering the CONSORT recommendations. Studies were collected from four databases: PubMed, Cochrane Library, Web of Science, and Embase. A total of 5960 articles were found. After filtering, 27 studies remained eligible for network meta-analysis. Moxonidine reduced blood pressure in sitting position statistically significantly after 8 weeks of treatment (SBP MD: 23.80; 95% CI: 17.45-30.15; DBP MD: 10.90; 95% CI: 8.45-13.35) compared to placebo. Moreover, moxonidine reduced blood pressure more effectively than enalapril; however, this difference was not significant (SBP MD: 3.10; 95% CI: -2.60-8.80; DBP MD: 1.30; 95% CI: -1.25-3.85). Dry mouth was experienced as a side effect in the case of all imidazoline receptor agonists. After 8 weeks of treatment, the appearance of dry mouth was highest with clonidine (OR: 9.27 95% CI: 4.70-18.29) and lowest with rilmenidine (OR: 6.46 95% CI: 0.85-49.13) compared to placebo. Somnolence was less frequent with moxonidine compared to rilmenidine (OR: 0.63 95% CI: 0.17-2.31). Imidazoline receptor agonists were nearly as effective as the first-line drugs in the examined studies. However, their utility as antihypertensives is limited due to their side effects. As a result, they are not first-line antihypertensives and should not be used in monotherapy. However, in the case of resistant hypertension, they are a viable option. According to our findings, from the point of view of safety and efficacy, moxonidine appears to be the best choice among imidazoline receptor agonists.

Presynaptic Adrenoceptors.

Presynaptic α2-adrenoceptors are localized on axon terminals of many noradrenergic and non-noradrenergic neurons in the peripheral and central nervous systems. Their activation by exogenous agonists leads to inhibition of the exocytotic release of noradrenaline and other transmitters from the neurons. Most often, the α2A-receptor subtype is involved in this inhibition. The chain of molecular events between receptor occupation and inhibition of the exocytotic release of transmitters has been determined. Physiologically released endogenous noradrenaline elicits retrograde autoinhibition of its own release. Some clonidine-like α2-receptor agonists have been used to treat hypertension. Dexmedetomidine is used for prolonged sedation in the intensive care; It also has a strong analgesic effect. The α2-receptor antagonist mirtazapine increases the noradrenaline concentration in the synaptic cleft by interrupting physiological autoinhibion of release. It belongs to the most effective antidepressive drugs. ß2-Adrenoceptors are also localized on axon terminals in the peripheral and central nervous systems. Their activation leads to enhanced transmitter release, however, they are not activated by endogenous adrenaline.

Thoracic spinal anesthesia with intrathecal sedation for lower back surgery: a retrospective cohort study.

Background: Spinal anesthesia (SA) is a good alternative to general anesthesia (GA) for spine surgery. Despite that, a few case series concern the use of thoracic spinal anesthesia for short-duration surgical interventions. In search of an alternative approach to GA and a better opioid-free modality, we aimed to investigate the safety, feasibility, and patient satisfaction of thoracic SA for spine surgery. Materials and methods: We analyzed retrospectively a cohort of 24 patients operated on for a degenerative and osteoporotic pathology of the lower thoracic and lumbar spine. Data was collected from medical records, including clinical notes, operative and anesthesia records, and patient questionnaires. Results: Twenty-one surgeries for herniated discs, two for degenerative spinal stenosis, and one for multi-level osteoporotic vertebral body fractures were performed under spinal anesthesia with intrathecal sedation. In all cases, we applied 0.5% isobaric bupivacaine and the following adjuvants: midazolam, clonidine or dexmedetomidine, and dexamethasone. We boosted the anesthesia with local ropivacaine due to inefficient sensory block in two patients. Nobody in the cohort received intravenous opioids, non-steroidal anti-inflammatory drugs, or additional sedation intraoperatively. Postoperative painkillers were upon the patient's request. No significant complications were detected. Conclusion: Thoracic spinal anesthesia incorporating adjuvants such as midazolam, clonidine or dexmedetomidine, and dexamethasone demonstrates not only efficient conditions for spine surgery, a favorable safety profile, high patient satisfaction, and intrathecal sedation but also effective opioid-free pain management.